LXR linux/fs/erofs/internal.h

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * Copyright (C) 2017-2018 HUAWEI, Inc.
   4 *             https://www.huawei.com/
   5 * Created by Gao Xiang <gaoxiang25@huawei.com>
   6 */
   7#ifndef __EROFS_INTERNAL_H
   8#define __EROFS_INTERNAL_H
   9
  10#include <linux/fs.h>
  11#include <linux/dcache.h>
  12#include <linux/mm.h>
  13#include <linux/pagemap.h>
  14#include <linux/bio.h>
  15#include <linux/buffer_head.h>
  16#include <linux/magic.h>
  17#include <linux/slab.h>
  18#include <linux/vmalloc.h>
  19#include "erofs_fs.h"
  20
  21/* redefine pr_fmt "erofs: " */
  22#undef pr_fmt
  23#define pr_fmt(fmt) "erofs: " fmt
  24
  25__printf(3, 4) void _erofs_err(struct super_block *sb,
  26                               const char *function, const char *fmt, ...);
  27#define erofs_err(sb, fmt, ...) \
  28        _erofs_err(sb, __func__, fmt "\n", ##__VA_ARGS__)
  29__printf(3, 4) void _erofs_info(struct super_block *sb,
  30                               const char *function, const char *fmt, ...);
  31#define erofs_info(sb, fmt, ...) \
  32        _erofs_info(sb, __func__, fmt "\n", ##__VA_ARGS__)
  33#ifdef CONFIG_EROFS_FS_DEBUG
  34#define erofs_dbg(x, ...)       pr_debug(x "\n", ##__VA_ARGS__)
  35#define DBG_BUGON               BUG_ON
  36#else
  37#define erofs_dbg(x, ...)       ((void)0)
  38#define DBG_BUGON(x)            ((void)(x))
  39#endif  /* !CONFIG_EROFS_FS_DEBUG */
  40
  41/* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
  42#define EROFS_SUPER_MAGIC   EROFS_SUPER_MAGIC_V1
  43
  44typedef u64 erofs_nid_t;
  45typedef u64 erofs_off_t;
  46/* data type for filesystem-wide blocks number */
  47typedef u32 erofs_blk_t;
  48
  49struct erofs_fs_context {
  50#ifdef CONFIG_EROFS_FS_ZIP
  51        /* current strategy of how to use managed cache */
  52        unsigned char cache_strategy;
  53        /* strategy of sync decompression (false - auto, true - force on) */
  54        bool readahead_sync_decompress;
  55
  56        /* threshold for decompression synchronously */
  57        unsigned int max_sync_decompress_pages;
  58#endif
  59        unsigned int mount_opt;
  60};
  61
  62/* all filesystem-wide lz4 configurations */
  63struct erofs_sb_lz4_info {
  64        /* # of pages needed for EROFS lz4 rolling decompression */
  65        u16 max_distance_pages;
  66        /* maximum possible blocks for pclusters in the filesystem */
  67        u16 max_pclusterblks;
  68};
  69
  70struct erofs_sb_info {
  71#ifdef CONFIG_EROFS_FS_ZIP
  72        /* list for all registered superblocks, mainly for shrinker */
  73        struct list_head list;
  74        struct mutex umount_mutex;
  75
  76        /* managed XArray arranged in physical block number */
  77        struct xarray managed_pslots;
  78
  79        unsigned int shrinker_run_no;
  80        u16 available_compr_algs;
  81
  82        /* pseudo inode to manage cached pages */
  83        struct inode *managed_cache;
  84
  85        struct erofs_sb_lz4_info lz4;
  86#endif  /* CONFIG_EROFS_FS_ZIP */
  87        u32 blocks;
  88        u32 meta_blkaddr;
  89#ifdef CONFIG_EROFS_FS_XATTR
  90        u32 xattr_blkaddr;
  91#endif
  92
  93        /* inode slot unit size in bit shift */
  94        unsigned char islotbits;
  95
  96        u32 sb_size;                    /* total superblock size */
  97        u32 build_time_nsec;
  98        u64 build_time;
  99
 100        /* what we really care is nid, rather than ino.. */
 101        erofs_nid_t root_nid;
 102        /* used for statfs, f_files - f_favail */
 103        u64 inos;
 104
 105        u8 uuid[16];                    /* 128-bit uuid for volume */
 106        u8 volume_name[16];             /* volume name */
 107        u32 feature_compat;
 108        u32 feature_incompat;
 109
 110        struct erofs_fs_context ctx;    /* options */
 111};
 112
 113#define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
 114#define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
 115
 116/* Mount flags set via mount options or defaults */
 117#define EROFS_MOUNT_XATTR_USER          0x00000010
 118#define EROFS_MOUNT_POSIX_ACL           0x00000020
 119
 120#define clear_opt(ctx, option)  ((ctx)->mount_opt &= ~EROFS_MOUNT_##option)
 121#define set_opt(ctx, option)    ((ctx)->mount_opt |= EROFS_MOUNT_##option)
 122#define test_opt(ctx, option)   ((ctx)->mount_opt & EROFS_MOUNT_##option)
 123
 124enum {
 125        EROFS_ZIP_CACHE_DISABLED,
 126        EROFS_ZIP_CACHE_READAHEAD,
 127        EROFS_ZIP_CACHE_READAROUND
 128};
 129
 130#ifdef CONFIG_EROFS_FS_ZIP
 131#define EROFS_LOCKED_MAGIC     (INT_MIN | 0xE0F510CCL)
 132
 133/* basic unit of the workstation of a super_block */
 134struct erofs_workgroup {
 135        /* the workgroup index in the workstation */
 136        pgoff_t index;
 137
 138        /* overall workgroup reference count */
 139        atomic_t refcount;
 140};
 141
 142#if defined(CONFIG_SMP)
 143static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
 144                                                 int val)
 145{
 146        preempt_disable();
 147        if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) {
 148                preempt_enable();
 149                return false;
 150        }
 151        return true;
 152}
 153
 154static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
 155                                            int orig_val)
 156{
 157        /*
 158         * other observers should notice all modifications
 159         * in the freezing period.
 160         */
 161        smp_mb();
 162        atomic_set(&grp->refcount, orig_val);
 163        preempt_enable();
 164}
 165
 166static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
 167{
 168        return atomic_cond_read_relaxed(&grp->refcount,
 169                                        VAL != EROFS_LOCKED_MAGIC);
 170}
 171#else
 172static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
 173                                                 int val)
 174{
 175        preempt_disable();
 176        /* no need to spin on UP platforms, let's just disable preemption. */
 177        if (val != atomic_read(&grp->refcount)) {
 178                preempt_enable();
 179                return false;
 180        }
 181        return true;
 182}
 183
 184static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
 185                                            int orig_val)
 186{
 187        preempt_enable();
 188}
 189
 190static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
 191{
 192        int v = atomic_read(&grp->refcount);
 193
 194        /* workgroup is never freezed on uniprocessor systems */
 195        DBG_BUGON(v == EROFS_LOCKED_MAGIC);
 196        return v;
 197}
 198#endif  /* !CONFIG_SMP */
 199#endif  /* !CONFIG_EROFS_FS_ZIP */
 200
 201/* we strictly follow PAGE_SIZE and no buffer head yet */
 202#define LOG_BLOCK_SIZE          PAGE_SHIFT
 203
 204#undef LOG_SECTORS_PER_BLOCK
 205#define LOG_SECTORS_PER_BLOCK   (PAGE_SHIFT - 9)
 206
 207#undef SECTORS_PER_BLOCK
 208#define SECTORS_PER_BLOCK       (1 << SECTORS_PER_BLOCK)
 209
 210#define EROFS_BLKSIZ            (1 << LOG_BLOCK_SIZE)
 211
 212#if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ)
 213#error erofs cannot be used in this platform
 214#endif
 215
 216#define ROOT_NID(sb)            ((sb)->root_nid)
 217
 218#define erofs_blknr(addr)       ((addr) / EROFS_BLKSIZ)
 219#define erofs_blkoff(addr)      ((addr) % EROFS_BLKSIZ)
 220#define blknr_to_addr(nr)       ((erofs_off_t)(nr) * EROFS_BLKSIZ)
 221
 222static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
 223{
 224        return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits);
 225}
 226
 227#define EROFS_FEATURE_FUNCS(name, compat, feature) \
 228static inline bool erofs_sb_has_##name(struct erofs_sb_info *sbi) \
 229{ \
 230        return sbi->feature_##compat & EROFS_FEATURE_##feature; \
 231}
 232
 233EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING)
 234EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS)
 235EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER)
 236EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)
 237
 238/* atomic flag definitions */
 239#define EROFS_I_EA_INITED_BIT   0
 240#define EROFS_I_Z_INITED_BIT    1
 241
 242/* bitlock definitions (arranged in reverse order) */
 243#define EROFS_I_BL_XATTR_BIT    (BITS_PER_LONG - 1)
 244#define EROFS_I_BL_Z_BIT        (BITS_PER_LONG - 2)
 245
 246struct erofs_inode {
 247        erofs_nid_t nid;
 248
 249        /* atomic flags (including bitlocks) */
 250        unsigned long flags;
 251
 252        unsigned char datalayout;
 253        unsigned char inode_isize;
 254        unsigned short xattr_isize;
 255
 256        unsigned int xattr_shared_count;
 257        unsigned int *xattr_shared_xattrs;
 258
 259        union {
 260                erofs_blk_t raw_blkaddr;
 261#ifdef CONFIG_EROFS_FS_ZIP
 262                struct {
 263                        unsigned short z_advise;
 264                        unsigned char  z_algorithmtype[2];
 265                        unsigned char  z_logical_clusterbits;
 266                };
 267#endif  /* CONFIG_EROFS_FS_ZIP */
 268        };
 269        /* the corresponding vfs inode */
 270        struct inode vfs_inode;
 271};
 272
 273#define EROFS_I(ptr)    \
 274        container_of(ptr, struct erofs_inode, vfs_inode)
 275
 276static inline unsigned long erofs_inode_datablocks(struct inode *inode)
 277{
 278        /* since i_size cannot be changed */
 279        return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
 280}
 281
 282static inline unsigned int erofs_bitrange(unsigned int value, unsigned int bit,
 283                                          unsigned int bits)
 284{
 285
 286        return (value >> bit) & ((1 << bits) - 1);
 287}
 288
 289
 290static inline unsigned int erofs_inode_version(unsigned int value)
 291{
 292        return erofs_bitrange(value, EROFS_I_VERSION_BIT,
 293                              EROFS_I_VERSION_BITS);
 294}
 295
 296static inline unsigned int erofs_inode_datalayout(unsigned int value)
 297{
 298        return erofs_bitrange(value, EROFS_I_DATALAYOUT_BIT,
 299                              EROFS_I_DATALAYOUT_BITS);
 300}
 301
 302extern const struct super_operations erofs_sops;
 303
 304extern const struct address_space_operations erofs_raw_access_aops;
 305extern const struct address_space_operations z_erofs_aops;
 306
 307/*
 308 * Logical to physical block mapping
 309 *
 310 * Different with other file systems, it is used for 2 access modes:
 311 *
 312 * 1) RAW access mode:
 313 *
 314 * Users pass a valid (m_lblk, m_lofs -- usually 0) pair,
 315 * and get the valid m_pblk, m_pofs and the longest m_len(in bytes).
 316 *
 317 * Note that m_lblk in the RAW access mode refers to the number of
 318 * the compressed ondisk block rather than the uncompressed
 319 * in-memory block for the compressed file.
 320 *
 321 * m_pofs equals to m_lofs except for the inline data page.
 322 *
 323 * 2) Normal access mode:
 324 *
 325 * If the inode is not compressed, it has no difference with
 326 * the RAW access mode. However, if the inode is compressed,
 327 * users should pass a valid (m_lblk, m_lofs) pair, and get
 328 * the needed m_pblk, m_pofs, m_len to get the compressed data
 329 * and the updated m_lblk, m_lofs which indicates the start
 330 * of the corresponding uncompressed data in the file.
 331 */
 332enum {
 333        BH_Zipped = BH_PrivateStart,
 334        BH_FullMapped,
 335};
 336
 337/* Has a disk mapping */
 338#define EROFS_MAP_MAPPED        (1 << BH_Mapped)
 339/* Located in metadata (could be copied from bd_inode) */
 340#define EROFS_MAP_META          (1 << BH_Meta)
 341/* The extent has been compressed */
 342#define EROFS_MAP_ZIPPED        (1 << BH_Zipped)
 343/* The length of extent is full */
 344#define EROFS_MAP_FULL_MAPPED   (1 << BH_FullMapped)
 345
 346struct erofs_map_blocks {
 347        erofs_off_t m_pa, m_la;
 348        u64 m_plen, m_llen;
 349
 350        unsigned int m_flags;
 351
 352        struct page *mpage;
 353};
 354
 355/* Flags used by erofs_map_blocks_flatmode() */
 356#define EROFS_GET_BLOCKS_RAW    0x0001
 357
 358/* zmap.c */
 359#ifdef CONFIG_EROFS_FS_ZIP
 360int z_erofs_fill_inode(struct inode *inode);
 361int z_erofs_map_blocks_iter(struct inode *inode,
 362                            struct erofs_map_blocks *map,
 363                            int flags);
 364#else
 365static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; }
 366static inline int z_erofs_map_blocks_iter(struct inode *inode,
 367                                          struct erofs_map_blocks *map,
 368                                          int flags)
 369{
 370        return -EOPNOTSUPP;
 371}
 372#endif  /* !CONFIG_EROFS_FS_ZIP */
 373
 374/* data.c */
 375struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr);
 376
 377/* inode.c */
 378static inline unsigned long erofs_inode_hash(erofs_nid_t nid)
 379{
 380#if BITS_PER_LONG == 32
 381        return (nid >> 32) ^ (nid & 0xffffffff);
 382#else
 383        return nid;
 384#endif
 385}
 386
 387extern const struct inode_operations erofs_generic_iops;
 388extern const struct inode_operations erofs_symlink_iops;
 389extern const struct inode_operations erofs_fast_symlink_iops;
 390
 391struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir);
 392int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 393                  struct kstat *stat, u32 request_mask,
 394                  unsigned int query_flags);
 395
 396/* namei.c */
 397extern const struct inode_operations erofs_dir_iops;
 398
 399int erofs_namei(struct inode *dir, struct qstr *name,
 400                erofs_nid_t *nid, unsigned int *d_type);
 401
 402/* dir.c */
 403extern const struct file_operations erofs_dir_fops;
 404
 405static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count)
 406{
 407        int retried = 0;
 408
 409        while (1) {
 410                void *p = vm_map_ram(pages, count, -1);
 411
 412                /* retry two more times (totally 3 times) */
 413                if (p || ++retried >= 3)
 414                        return p;
 415                vm_unmap_aliases();
 416        }
 417        return NULL;
 418}
 419
 420/* pcpubuf.c */
 421void *erofs_get_pcpubuf(unsigned int requiredpages);
 422void erofs_put_pcpubuf(void *ptr);
 423int erofs_pcpubuf_growsize(unsigned int nrpages);
 424void erofs_pcpubuf_init(void);
 425void erofs_pcpubuf_exit(void);
 426
 427/* utils.c / zdata.c */
 428struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);
 429
 430#ifdef CONFIG_EROFS_FS_ZIP
 431int erofs_workgroup_put(struct erofs_workgroup *grp);
 432struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
 433                                             pgoff_t index);
 434struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
 435                                               struct erofs_workgroup *grp);
 436void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
 437void erofs_shrinker_register(struct super_block *sb);
 438void erofs_shrinker_unregister(struct super_block *sb);
 439int __init erofs_init_shrinker(void);
 440void erofs_exit_shrinker(void);
 441int __init z_erofs_init_zip_subsystem(void);
 442void z_erofs_exit_zip_subsystem(void);
 443int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
 444                                       struct erofs_workgroup *egrp);
 445int erofs_try_to_free_cached_page(struct address_space *mapping,
 446                                  struct page *page);
 447int z_erofs_load_lz4_config(struct super_block *sb,
 448                            struct erofs_super_block *dsb,
 449                            struct z_erofs_lz4_cfgs *lz4, int len);
 450#else
 451static inline void erofs_shrinker_register(struct super_block *sb) {}
 452static inline void erofs_shrinker_unregister(struct super_block *sb) {}
 453static inline int erofs_init_shrinker(void) { return 0; }
 454static inline void erofs_exit_shrinker(void) {}
 455static inline int z_erofs_init_zip_subsystem(void) { return 0; }
 456static inline void z_erofs_exit_zip_subsystem(void) {}
 457static inline int z_erofs_load_lz4_config(struct super_block *sb,
 458                                  struct erofs_super_block *dsb,
 459                                  struct z_erofs_lz4_cfgs *lz4, int len)
 460{
 461        if (lz4 || dsb->u1.lz4_max_distance) {
 462                erofs_err(sb, "lz4 algorithm isn't enabled");
 463                return -EINVAL;
 464        }
 465        return 0;
 466}
 467#endif  /* !CONFIG_EROFS_FS_ZIP */
 468
 469#define EFSCORRUPTED    EUCLEAN         /* Filesystem is corrupted */
 470
 471#endif  /* __EROFS_INTERNAL_H */
 472
 473